Pyrazinium Salts as Efficient Organocatalysts of Mild Oxidations with Hydrogen Peroxide was written by Menova, Petra;Kafka, Frantisek;Dvorakova, Hana;Gunnoo, Smita;Sanda, Miloslav;Cibulka, Radek. And the article was included in Advanced Synthesis & Catalysis in 2011.Category: pyrazines This article mentions the following:
A series of 3-substituted pyrazinium tetrafluoroborates was prepared as simple analogs of flavinium salts which are efficient organocatalysts for oxidations with hydrogen peroxide. It was shown that pyrazinium derivatives with an electron-withdrawing substituent catalyze mild oxidations of sulfides to sulfoxides and Baeyer-Villiger oxidations in a similar way to flavinium catalysts. The most reactive catalyst, 3-cyanopyrazinium tetrafluoroborate, was efficiently employed in preparative sulfoxidations of aromatic and aliphatic sulfides as well as in Baeyer-Villiger oxidations of cyclobutanones. A proposed mechanism for the catalysis is based on the formation of pyrazine hydroperoxide which is the agent oxidizing the substrate. In the experiment, the researchers used many compounds, for example, Ethyl pyrazine-2-carboxylate (cas: 6924-68-1Category: pyrazines).
Ethyl pyrazine-2-carboxylate (cas: 6924-68-1) belongs to pyrazine derivatives. Pyrazinesare six-membered aromatic heterocyclic organic compounds with two nitrogen atoms at 1,4-positions. Pyrazine is a weaker base (pKb = 13.4) than pyridine (pKb = 8.8), pyrimidine (pKb = 12.7). Pyrazines undergo nearly all of the same reactions as pyrimidines, from nucleophilic substitution (SNAr) to palladium-catalyzed cross coupling reactions.Category: pyrazines